The Centers for Disease Control and Prevention has warned that as schools reopen this fall, the number of unvaccinated children and adolescents could create a “serious public health threat” of outbreaks of preventable illnesses like measles and whooping cough.
Stay-home orders and other disruptions in the early months of the pandemic led to a dramatic drop in the number of students vaccinated against typical childhood diseases, the CDC found in a newly published study. While families have started to bring their children back for doctor’s visits, in many cases, it won’t be enough to recover the same level of protection for the large groups of students who will return to full-time, in-person learning this year without a major effort by schools.
In the new study, the CDC tracked the doses of four kinds of vaccines given to children and adolescents in nine states plus New York City from March through May and June through September of last year, and compared it to the doses given during the same two time periods in 2018 and 2019. It found that childhood immunizations crashed last spring, when most families had been ordered to stay home and haven’t recovered since.
That slow recovery is in large part, researchers say, because schools have not stringently enforced standard vaccination requirements as many students returned to virtual and hybrid classes. Now, new CDC guidance permitting COVID-19 vaccines to be coupled with other immunizations could allow schools to set up universal vaccination drives before fall.
“Pediatric outbreaks of vaccine-preventable diseases have the potential to derail efforts to reopen schools for the 2021–22 academic year and further delay nationwide efforts to return students to the classroom,” researchers wrote. “Health-care systems and other social institutions are already overburdened by the COVID-19 pandemic, and vaccine-preventable disease outbreaks can lead to loss of in-person learning and further overwhelm community resources and contribute to morbidity and mortality.”
There is a downside to keeping children home
In the study, CDC researchers tracked four common vaccines, including two typically given to young children: DTaP, to prevent diphtheria, tetanus, and pertussis (commonly known as whooping cough) and MMR, to prevent measles, mumps, and rubella (also called German measles). The other two vaccines are scheduled for those ages 13-17, to prevent human papillomavirus, a common sexually transmitted disease which can cause cancer, and Tdap, a booster to further prevent tetanus, diphtheria, and whooping cough.
While these illnesses have long been held in check by immunizations, many are significantly more virulent than COVID-19. For example, the World Health Organization estimates each person with COVID-19 can spread it to about three others. But someone with whooping cough can infect more than five others on average, and someone with measles can infect 12 to 18 other people. There have only been a handful of cases of measles or whooping cough in the United States since the pandemic started—the quarantines put in place to prevent the spread of coronavirus worked equally well on other diseases—but there was a spike in both diseases in the year before the pandemic, in part due to a longer-term trend of falling childhood vaccination rates.
That problem worsened in the first spring of the pandemic, when New York City and eight of the nine states studied passed stay-home orders, the CDC found. Compared with doses in 2018 and 2019, the number of immunizations given in March through May of 2020 against diphtheria, tetanus, and whooping cough dropped more than 66 percent among adolescents and more than 60 percent among elementary and preschool-age children. Measles vaccinations during the same time fell by more than 63 percent among children ages 2-8. And vaccinations against human papillomavirus dropped by more than 63 percent for preteens and more than 70 percent for teenagers in that period.
The United States was not alone. European researchers found a nearly 20 percent drop in measles vaccinations during spring 2020. In one study, 60 percent of parents in a nurse visiting program in the United Kingdom reported canceling or postponing their children’s vaccinations during the pandemic, in part due to fear their children could be exposed to the virus.
By September, when many states had begun to allow people to come out of quarantine, more families began to bring their children in for scheduled shots, but slowly. Vaccinations against diphtheria, tetanus, and whooping cough that fall were nearly 7 percent lower for children ages 2-8, more than 21 percent lower for those ages 9-12, and down by 30 percent for teenagers, compared to the vaccinations given in 2018 and 2019. Similarly, MMR doses dipped more than 11 percent and HPV vaccinations were down more than 12 percent for preteens and more than 28 percent for teenagers.
In June, the Biden administration launched a “Vaccine Month of Action” intended to encourage families to get themselves and their children 12 and older vaccinated against COVID-19 before next school year. While no vaccine now exists for children younger than 12 now, at least one vaccine manufacturer expects to have doses available for younger children sometime early in the 2021-22 school year.
States and schools are still debating whether and how to require COVID-19 vaccinations for children to return to school, but standard immunizations against childhood illnesses like measles and whooping cough have been legally required in all states for decades, and schools have found campus-based vaccination clinics and drives can fill gaps in immunity among their populations quickly.